Arrangement for forming solids of rotation by a cross wedge rolling process with three rolls

ABSTRACT

A rolling mill with three cylinders, supporting exchangeable wedge shaped forming bodies for cross wedge rolling of solids of rotation is provided with forming bodies having forming ledges and triangular cavities, enabling the external parts of one forming body to enter the cavity of an adjacent forming body so that the forming ledges may for rolling of objects of a small diameter come close to the axis of the rolled object.

United States Patent [191 Holub [451 Mar. 11, 1975 1 ARRANGEMENT FORFORMING SOLIDS OF ROTATION BY A CROSS WEDGE ROLLING PROCESS WITH THREEROLLS [75] Inventor: JiriHolub,Prague,Czechoslovakia 73] Assignee:Vyzkumny ustav tvarecich streju a technologie tvareni, Brno,Czechoslovakia [22] Filed: Apr. 11, 1974 [21] Appl. No.: 460,168

[30] Foreign Application Priority Data Aprv 13, 1973 Czechoslovakia2635-73 [52] US. Cl. 72/107 [51] Int. Cl. B2lh 8/02 [58] Field of Search72/71, 107

[56] References Cited UNITED STATES PATENTS 412,626 10/1889 Jones 72/1071,493,836 5/1924 Wurster 72/107 Primary Examiner-Lowell A. Larson [57]ABSTRACT A rolling mill with three cylinders, supporting exchangeablewedge shaped forming bodies for cross wedge rolling of solids ofrotation is provided with forming bodies having forming ledges andtriangular cavities, enabling the external parts of one forming body toenter the cavity of an adjacent forming body so that the forming ledgesmay for rolling of objects of a small diameter come close to the axis ofthe rolled object.

1 Claim, 7 Drawing Figures ARRANGEMENT FOR FORMING SOLIDS OF ROTATION BYA CROSS WEDGE ROLLING PROCESS WITH THREE ROLLS BACKGROUND OF THEINVENTION This invention relates to an arrangement for forming solids ofrotation by a cross wedge rolling process with three rolls and withexchangeable wedge shaped forming bodies.

The forming of round or mutliedged objects by a cross wedge hot rollingprocess is performed by two or three rolls with wedge shaped tools,fixed or provided on said rolls. A twin roll rolling mill is capable ofrolling one size of rolls products within the range of their size andwithin a large range of diameters and lengths. Three roll rolling millsare however in this respect limited both regarding rolled diameters androlled lengths. The maximum diameters of three rolls and of the toolsare limited by the capability of rolling the object of required diameterwithout a danger that the tools are making mutual contact. It isimpossible to roll on actual three roll rolling mills products of smalldiameters with currently used tools of a large diameter and vice versa,i.e. with tools of small diameter to roll products of larger diameters,in the latter case due to lack of strength of the rolling device. Toolsof a small diameter have a small circumference and consequently are capable of rolling short lengths only.

SUMMARY OF THE INVENTION It is an object of this invention to removethese drawbacks and to provide a rolling mill with three rolls arrangedsymmetrically with respect to the axis of the rolled object, supportingexchangeable forming tools and rotating in the same direction, capableof rolling solids of rotation having a relatively wide range ofdiameters and with lengths which are approximately equal for the largestand smallest diameters. According to this invention the wedge shapedforming tools have forming ledges of different thickness correspondingto the diameter dimension of the rolled object. The forming tools arealso provided with a triangular cavity of sufficient depth and width toenable the rolling of objects of smaller diameter. A free passage of theexternal part of the wedge shaped tool through the triangular cavity ofthe adjacent wedge shaped tool is provided so that one wedge shaped toolmay always enter the cavity of its adjacent wedge shaped tool. Thisenables the use a of one dimension of the diameter for the workingcylinders of a rolling mill of a size determined by the range ofdiameters of objects to be rolled. Within this range objects from thesmallest to the largest diameter at approximately equal lengths for boththe smallest and the largest diameters of rolled objects may be rolled.

DESCRIPTION OF DRAWINGS An exemplary embodiment of the object of thisinvention is shown in the attached drawings where,

where FIG. 1 is a side view of the rolls, rolling an object of a largerdiameter;

FIG. 2, the same view when rolling an object of medium diameter;

FIG. 3. the same view when rolling object of a small diameter;

FIG. 4 is a cross sectional view of wedge shaped forming bodies rollinga solid of rotation prior to their entrance into cavities of adjacentforming bodies, the

section being taken along a plane indicated in FIG. 6 by B-B;

FIG. 5 is the same view after parts of the wedge shaped forming bodieshave entered cavities of adjacent forming bodies;

FIG. 6 is a top view of a forming body with a part of an adjacent bodypenetrated into its cavity, the latter forming body seen in a sectionalview taken along a plane indicated in FIG. 5 by the line AA and FIG. 7is a sectional view of the forming body taken along a plane, indicatedin FIG. 6 by C-C.

DESCRIPTION OF PREFERRED EMBODIMENT FIG. 1 shows a three roll rollingmill where wedge shaped tools 1",2", 3" of equal dimensions and shapeare fixed on three cylinders 4 of equal diameter D, rotating in the samedirection and arranged symmetrically with respect to the axis of therolled object 5". The rolled object 5" rotating in the oppositedirection is situated in the space between the three cylinders. Aproduct of relatively large diameter is rolled in this case, the toolson the three cylinders therefore do not come in mutual contact.

FIG. 2 shows the rolling ofa product 5' of halfthe diameter as inFIG. 1. The diameter D of the cylinders 4 is the same as in FIG. 1, thetools I, 2, 3' are however higher and mutually penetrating each other.The tool 1' penetrates into the space of tool 2, the tool 2' into thespace of tool 3' and tool 3' into the space tool 1.

FIG. 3 shows the rolling ofa product 5 of the smallest diameter. Thediameter of the cylinders 4 is the same as in the preceding cases, thetools 1, 2, 3 are however still higher. The mutual penetration of thetools is also to a larger depth.

FIG. 4 shows a cross section of three wedge shaped forming tools 1, 2,3, the section taken along the plane, indicated in FIG. 6 by 8-8. Thethree tools move in the direction of the indicated arrows and are in aposition where their tips 6 start to penetrate into cavities ofneighboring tools.

In FIG. 5 the tools proceeded in their movements from the position shownin FIG. 4 and have entered by their tips deeper into cavities ofneighboring tools.

The triangular cavities of all tools must be as large to enable a safepassage of the wedge of the neighboring tool into this cavity. Thedimensions (width and depth) and the external dimensions of the enteringwedges are determined by the width b of the forming ledges, which has tobe conformed with the depth into which the tools are entering. The morethe tools mutually penetrate (in case of rolling objects of smalldiameter) a smaller width b of the ledges and a larger depth c of thecavity is required and vice versa, for a smaller penetration, a largerwidth b of the ledges and a smaller depth c of the cavity is required.These rules are conforming with the forces acting on the forming ledgesfor rolling and also conform with the required dimensions of themutually widening forming surfaces 10 and of the surfaces 11. A materialof smaller diameter is formed with smaller forces and with smallerdimensions of the forming surfaces 10 and of the smoothening surfaces11. Materials of larger dimensions are formed with larger forces actingon wider forming ledges having larger dimensions of the forming surfaces10 and of the smoothening surfaces 11.

FIG. 6 shows a top view of the tool I viewed in the direction of thearrow S from FIG. 5 and a cross section 9 of the tool 3 along a planeindicated in FIG. 5 by A-A. As all three tools are of quite equal shapewe use simultaneously the tool 1 from FIG. 6 for determination of theshape of the cross section 9 of tool 3 in the plane AA in order to havea safe clearance between the cavity of one tool and the other toolpenetrating into this cavity. In FIG. 6 the points 7 8 shows the widesplaces of the penetrated tips of the tool 3 and points 7 8 showspositions of points 7, 8 with respect to the cavity of the tool 1. Inthe course of a further movement of the forming ledges in the directionof the arrows, the triangular cavity of the tool 1 will widen and thepenetrating wedge of the tool 3 will simultaneously widen in the samemanner. The tool 3 will freely pass through tool 1, tool 1 will passthrough tool 2 and tool 2 will equally pass through tool 3.

What is claimed is:

1. An arrangement for forming of solids of rotation by cross wedgerolling comprising three working cylinders rotating in the samedirection and symmetrically arranged with respect to the axis of therolled object,

each of said working cylinders supporting an exchangeable wedge shapedforming tool, said forming tools having forming ledges converging in thedirection of their rotating movement, saidforming ledges having athickness corresponding to the dimensions of the diameters of objects tobe rolled, a triangular cavity in each forming tool of sufficient depthand width between said forming ledges of each tool, to enable therolling ofobjects of small diameter. a free passage in the external partof the wedge shaped tool through the triangular cavity of the adjacentwedge shaped tool so that always one wedge shaped tool may enter thecavity of its adjacent wedge shaped tool. whereby one dimension of thediameter of said working cylinders ofa selected size determined by therange of diameters of objects to be rolled within this range rollsobjects from the smallest to the largest diameter of this range atapproximately equal lengths both for the smallest and for the largestdiameters of the objects to be rolled.

1. An arrangement for forming of solids of rotation by cross wedgerolling comprising three working cylinders rotating in the samedirection and symmetrically arranged with respect to the axis of therolled object, each of said working cylinders supporting an exchangeablewedge shaped forming tool, said forming tools having forming ledgesconverging in the direction of their rotating movement, said formingledges having a thickness corresponding to the dimensions of thediameters of objects to be rolled, a triangular cavity in each formingtool of sufficient depth and width between said forming ledges of eachtool, to enable the rolling of objects of small diameter, a free passagein the external part of the wedge shaped tool through the triangularcavity of the adjacent wedge shaped tool so that always one wedge shapedtool may enter the cavity of its adjacent wedge shaped tool, whereby onedimension of the diameter of said working cylinders of a selected sizedetermined by the range of diameters of objects to be rolled within thisrange rolls objects from the smallest to the largest diameter of thisrange at approximately equal lengths both for the smallest and for thelargest diameters of the objects to be rolled.